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-rw-r--r--arch/arm/mach-omap2/cm.c70
1 files changed, 70 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/cm.c b/arch/arm/mach-omap2/cm.c
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1/*
2 * OMAP2/3 CM module functions
3 *
4 * Copyright (C) 2009 Nokia Corporation
5 * Paul Walmsley
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/types.h>
15#include <linux/delay.h>
16#include <linux/spinlock.h>
17#include <linux/list.h>
18#include <linux/errno.h>
19#include <linux/err.h>
20#include <linux/io.h>
21
22#include <asm/atomic.h>
23
24#include "cm.h"
25#include "cm-regbits-24xx.h"
26#include "cm-regbits-34xx.h"
27
28/* MAX_MODULE_READY_TIME: max milliseconds for module to leave idle */
29#define MAX_MODULE_READY_TIME 20000
30
31static const u8 cm_idlest_offs[] = {
32 CM_IDLEST1, CM_IDLEST2, OMAP2430_CM_IDLEST3
33};
34
35/**
36 * omap2_cm_wait_idlest_ready - wait for a module to leave idle or standby
37 * @prcm_mod: PRCM module offset
38 * @idlest_id: CM_IDLESTx register ID (i.e., x = 1, 2, 3)
39 * @idlest_shift: shift of the bit in the CM_IDLEST* register to check
40 *
41 * XXX document
42 */
43int omap2_cm_wait_module_ready(s16 prcm_mod, u8 idlest_id, u8 idlest_shift)
44{
45 int ena = 0, i = 0;
46 u8 cm_idlest_reg;
47 u32 mask;
48
49 if (!idlest_id || (idlest_id > ARRAY_SIZE(cm_idlest_offs)))
50 return -EINVAL;
51
52 cm_idlest_reg = cm_idlest_offs[idlest_id - 1];
53
54 if (cpu_is_omap24xx())
55 ena = idlest_shift;
56 else if (cpu_is_omap34xx())
57 ena = 0;
58 else
59 BUG();
60
61 mask = 1 << idlest_shift;
62
63 /* XXX should be OMAP2 CM */
64 while (((cm_read_mod_reg(prcm_mod, cm_idlest_reg) & mask) != ena) &&
65 (i++ < MAX_MODULE_READY_TIME))
66 udelay(1);
67
68 return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
69}
70